Loads a 128-bit value atomically.
__int64 __load128( __int64 volatile * Source, __int64 *DestinationHigh ); __int64 __load128_acq( __int64 volatile * Source, __int64 *DestinationHigh );
- [in] Source
Pointer to the 128-bit source value.
- [out] DestinationHigh
Pointer to a memory location where the most significant 64-bit quadword of the 128-bit loaded value is stored.
The __load128 function performs an atomic 128-bit read from the source memory location. The Source pointer should point to a 16-byte aligned memory location.
These functions are not general purpose 128-bit intrinsics. These functions should only be used if you really need 128-bit atomic loads. You get better performance with regular 64-bit operations.
Note that the intrinsic form of this function has a leading underscore in the name. Also note that these functions are always expanded as intrinsics. That means you might use /Oi or #pragma intrinsic, but it is not required.
The __load128_acq intrinsic function is the same as the corresponding function without the _acq suffix except that the operation is performed with acquire semantics.
In Visual C++ 2005, these functions behave as read-write barriers. For more information, see _ReadWriteBarrier.